The disc valve element in a gerotor motor of the disc valve type is pressed against a port plate element. The surface between the disc valve and the port valve forms a sealing surface, so that fluid from high-pressure chambers in the gear set cannot get in touch with fluid from the low-pressure chambers. On the rear of the disc valve is arranged a sealing element, and the surface between the disc valve and the sealing element also forms a sealing surface, so that the high and low pressure chambers do not fluidly connect with each other. The sealing is partly secured by a spring element acting upon the sealing element in the direction of the gear set, partly by accurately adapted areas acted upon by the fluid pressure from high-pressure and low-pressure.
Experience and simulation results show that the disc valve element is slightly deformed when the motor is loaded and the pressure increases. Part of the deformation takes place because of torsional forces around the axis of the valve causing the two sealing surfaces to deform and to fail to maintain their intimate contact. This causes a leakage from the high-pressure chamber to the low-pressure chamber. This leakage contributes to a deterioration of the motor efficiency and is therefore not desirable. The torsional forces around the axis of the valve are avoided when the surface mass of the valve material on the front of the valve (where the commutation slots are located) is equal and symmetrical to the mass of material on the rear of the valve.
It is therefore a principal object of this invention to provide a means for optimizing the disc valve in a gerotor motor.
A further object of the invention is to provide means in a gerotor motor for equalizing torsional forces within a disc valve of the motor to reduce or eliminate distortion and deformation of sealing surfaces in the valves, to overcome fluid leakage.
A still further object of this invention is to impose blind slots in the rear side of the valve of a gerotor motor to balance the torsional forces within the valve to reduce distortion of the sealing surfaces and to decrease the fluid loss caused by such distortion.
These and other objects will be apparent to those skilled in the art.
A gerotor motor has a housing located adjacent a port plate. The housing has two fluid chambers on opposite sides of a disc valve. The disc valve is in sealing surface engagement with the port plate to prevent fluid from moving between the fluid chambers. The valve assembly has forward and rearward sides and has substantially equal volumes of material removed therefrom so as to balance the disc valve against any torsional forces imposed on the valve assembly which might otherwise deflect the valve assembly to interfere with its sealing relationship with the port plate.